Degenerative changes were common in brain magnetic resonance imaging in patients with newly diagnosed Parkinson's disease in a population-based cohort.

The aim of this study was to investigate newly diagnosed patients with Parkinson's disease (PD) with structural magnetic resonance imaging (MRI), to compare them with healthy controls, to relate the findings to clinical subtypes--tremor dominant (TD) or postural instability and gait difficulty (PIGD)--and to investigate the relationship between both the duration from onset of symptoms to diagnosis and the severity of symptoms and the MRI findings. Patients with a definite PD diagnosis were compared to patients with a probable PD diagnosis. We hypothesized that the PIGD subtype, the probable PD group, a greater symptom severity and a longer symptom duration would all be associated with more frequent pathological findings. Sixty-six PD patients were included and examined with MRI, 35 with the PIGD subtype and 23 with the TD subtype. Fifty-three had definite PD and 13 probable PD. Thirty healthy individuals, matched for age and sex, served as controls. Degenerative changes in the cerebellar cortex and the superior cerebellar peduncle were significantly more common in the probable PD group than in the controls, suggesting the possibility of an emerging atypical parkinsonian disorder. No significant MRI differences were found between definite PD and controls, between definite PD and probable PD, nor between PIGD and TD. No significant associations were found between duration to diagnosis and MRI results, nor between severity of symptoms and MRI results. Thus, although pathological MRI findings were common they can not be used to separate subgroups of PD in newly diagnosed patients.